“…The metal ion is usually coordinated by nitrogen, oxygen or sulfur atoms belonging to amino acids in the polypeptide chain and/or a macro-cyclic ligand incorporated into the protein [2,3]. The presence of the metal ion allows metalloenzymes to perform functions such as redox reactions that cannot be performed by the limited set of functional groups found in amino acids [1]. Metalloproteins play important roles in structural stability and complex formation [4][5][6][7][8], gene expression regulation and alteration [9][10][11][12], DNA processing [13], signaling processes and cellular event [14], transport [11,15,16], metabolism control [15,17], antibody recognition [18] and other biological processes such as cellular respiration, photosynthesis, nitrogen fixation and antioxidant defense [19].…”